Helios Crash
Joined: Mar 2007
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From: FL410
Ifixplanes...
Oh yeah.. you're right. Sorry I was upstairs and the lack of oxygen was getting to me... I was indeed confusing the steady and intermittent warning horns.
Nevertheless I think I made a point by mistake, which is that it is a potentially confusing setup. The fact does remain though that someone somewhere thinks the system is such to warrant the fitting of the Takeoff Config/Cabin Alt annunciators on both the left and right forward panels on new 737s. That bit was not rubbish.
Oh yeah.. you're right. Sorry I was upstairs and the lack of oxygen was getting to me... I was indeed confusing the steady and intermittent warning horns.
Nevertheless I think I made a point by mistake, which is that it is a potentially confusing setup. The fact does remain though that someone somewhere thinks the system is such to warrant the fitting of the Takeoff Config/Cabin Alt annunciators on both the left and right forward panels on new 737s. That bit was not rubbish.
Joined: Apr 2004
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From: near EDDF
Originally Posted by D O Guerrero
...The fact does remain though that someone somewhere thinks the system is such to warrant the fitting of the Takeoff Config/Cabin Alt annunciators on both the left and right forward panels on new 737s. ...
Maybe because english is not my native language...
Joined: Mar 2007
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From: FL410
All I'm saying is that Boeing are now fitting these lights to clarify the meaning of the warning horn when it goes off. I'm not sure of the schedule or if they are being retro-fitted, but they are certainly now standard on 737NG currently coming off the production line.
The point I am making is that the fact they are being fitted now, must mean that there is an acknowledged problem with the warning horn and its interpretation. Sorry If I'm wording it badly...
The point I am making is that the fact they are being fitted now, must mean that there is an acknowledged problem with the warning horn and its interpretation. Sorry If I'm wording it badly...
Joined: Mar 2008
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From: London
From the report:
4. The use of the same aural warning to signify two different situations (Takeoff Configuration and Cabin Altitude) was not consistent with good Human Factors principles.
5. Over the past several years, numerous incidents had been reported involving confusion between the Takeoff Configuration Warning and Cabin Altitude Warning on the Boeing 737 and NASA’s ASRS office had alerted the manufacturer and the aviation industry..
6. Numerous incidents had been reported world-wide involving cabin pressurization problems on the Boeing 737. A number of remedial actions had been taken by the manufacturer since 2000, but the measures taken had been inadequate and ineffective in preventing further similar incidents and accidents.
5. Over the past several years, numerous incidents had been reported involving confusion between the Takeoff Configuration Warning and Cabin Altitude Warning on the Boeing 737 and NASA’s ASRS office had alerted the manufacturer and the aviation industry..
6. Numerous incidents had been reported world-wide involving cabin pressurization problems on the Boeing 737. A number of remedial actions had been taken by the manufacturer since 2000, but the measures taken had been inadequate and ineffective in preventing further similar incidents and accidents.
Joined: Feb 2002
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From: The Sandpit
Actually you CAN get a take-off warning in the air. It occurs if the ground spoiler interlock valve is still open with the a/c in the air and flaps up.
I don't know at what height the a/c would be clean but I would have thought it would be a far bit before 10000ft (cabin px at which the cab alt horn sounds)
For me the give away as to the reason for the horn, is the point at which the horn first sounded. 10000ft is not high enough to couse hypoxia and reasoned thought should have deduced the cause. However. The fact that so many holes in the cheese lined up staggers me.
Incorrect sw pos after maintenance
Incorrect pre-flight checks (surely the elevation must be set on the controller and this is right next to the auto/man switch), after t.o checks, etc.
Poor (appalling) CRM
Cabin crew not aware of emergency access code to cockpit (or scared to use it?)
There were at least 5 layers where it all lined up.
I also have worked with one of the engineers involved and if he is one of those to be prosecuted then that will be a sad state of affairs. We need to learn from this and prosecution will drive untold nails into the no blame culture coffin.
I don't know at what height the a/c would be clean but I would have thought it would be a far bit before 10000ft (cabin px at which the cab alt horn sounds)
For me the give away as to the reason for the horn, is the point at which the horn first sounded. 10000ft is not high enough to couse hypoxia and reasoned thought should have deduced the cause. However. The fact that so many holes in the cheese lined up staggers me.
Incorrect sw pos after maintenance
Incorrect pre-flight checks (surely the elevation must be set on the controller and this is right next to the auto/man switch), after t.o checks, etc.
Poor (appalling) CRM
Cabin crew not aware of emergency access code to cockpit (or scared to use it?)
There were at least 5 layers where it all lined up.
I also have worked with one of the engineers involved and if he is one of those to be prosecuted then that will be a sad state of affairs. We need to learn from this and prosecution will drive untold nails into the no blame culture coffin.
Joined: Apr 2004
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From: near EDDF
Originally Posted by Litebulbs
At the time of the incident, the switch was not in the incorrect position after maintenance. The maintenance manual has now been changed to reflect where the switch should be after maintenance.
Joined: Aug 2008
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From: North America
Thank you for the link
IFixPlanes, thank you for posting the link to this accident report. Its an informative “read”. There were several imbedded surprises as there usually are. I depart today on a 3 day 737 trip, looks like I have my layover reading material.
Joined: Oct 2007
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From: north of london
I have worked with one of the engineers in question..... he is one of the most experienced, knowledgable engineers ive ever worked with... it will be a sad day if he is charged in relation to this accident.
Regardless of where the switch was left after maintenance... it should still have been picked up by the crew.
Regardless of where the switch was left after maintenance... it should still have been picked up by the crew.
Joined: Feb 2005
Aviation Qualifications: ATPL
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From: Correr es mi destino por no llevar papel
So if i got it right, there's no red "EXCESSIVE CABIN ALT" light on 737 to go with warning horn? You get the horn blasting and cabin altimeter with funny reading and that's it?!?
Per Ardua ad Astraeus
Joined: Mar 2000
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From: UK
Originally Posted by mono
Actually you CAN get a take-off warning in the air. It occurs if the ground spoiler interlock valve is still open with the a/c in the air and flaps up.
Joined: Apr 2005
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From: UK
Lots of talk about the position of the press switch.
1/ Is the switch position recorded on any device ?
If the answer is no, then we do not know who placed the switch to the position it was found in after the event or when it was placed in this position.
Another point to remember, some pilots do check A/B or 1/2 normal systems for indicated defects plus an operation check of the Man Mode/Stby Mode before flight.
Have even seen some very keen pilots using Man Mode to drive OFV out of normal position and then check A/B can control OFV, a pro-active check may be, but that system can become very very important if problems ocour in flight, plus with smoke, pilots need to have good skills using those little buttons with poss poor view.
Thoughts with all involved.
1/ Is the switch position recorded on any device ?
If the answer is no, then we do not know who placed the switch to the position it was found in after the event or when it was placed in this position.
Another point to remember, some pilots do check A/B or 1/2 normal systems for indicated defects plus an operation check of the Man Mode/Stby Mode before flight.
Have even seen some very keen pilots using Man Mode to drive OFV out of normal position and then check A/B can control OFV, a pro-active check may be, but that system can become very very important if problems ocour in flight, plus with smoke, pilots need to have good skills using those little buttons with poss poor view.
Thoughts with all involved.
Joined: Feb 2002
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From: The Sandpit
BOAC,
Sorry actually a type error!
The classic indeed can only have an intermittent horn in the air for a cabin altitude excedance.
The NG however, can have the intermittent horn on in the air for either a cabin alt exceedance OR a fault with the ground spoiler system.
The opening statement from the MM 31-53-00 page 2 reads
The takeoff warning function gives an aural warning sound if the airplane is in an unsafe condition during takoff or if the ground spoiler interlock valve remains open after takeoff
The conditions for in air warning; are ground spoiler interlock valve open and leading edge flaps and slats not extended.
Sorry for the thread creep.
Sorry actually a type error!
The classic indeed can only have an intermittent horn in the air for a cabin altitude excedance.
The NG however, can have the intermittent horn on in the air for either a cabin alt exceedance OR a fault with the ground spoiler system.
The opening statement from the MM 31-53-00 page 2 reads
The takeoff warning function gives an aural warning sound if the airplane is in an unsafe condition during takoff or if the ground spoiler interlock valve remains open after takeoff
The conditions for in air warning; are ground spoiler interlock valve open and leading edge flaps and slats not extended.
Sorry for the thread creep.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
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From: UK
I'll take your word for it, but the message that came 'loud and clear' from Boeing was that the intermittent horn in the air could 'only be pressurisation', so that is interesting. However, our drill remains the same - we ASSUME loss of cabin pressure and act accordingly until we prove otherwise. No mention of this 'interlock' in any of our owners' handbooks or our MEL. I guess a failure of the A/G switching in general could produce a warning too when the flaps are retracted.
Joined: May 2007
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From: Europe
prosecution will drive untold nails into the no blame culture coffin.
There IS a "just" culture, and if not there should be, which seeks to analyse and search out the root cause of why an error occured, rather than simply blaming the nearest mechanic in sight. The MEDA approach, in fact, in one form or another, where maintenance is concerned.
But if the root cause turns out to be that someone royally screwed up, through culpable negligence, or knowingly ignoring instructions, procedures etc, he or she will get blamed, partially or wholly, and perhaps punished, and rightly so.
It is pretty obvious to me that this cannot be said of any engineer, at least, in the Helios case, but I'm a zillion miles from that loop and only know what I've read.
Joined: Feb 2007
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From: UK
After reading this thread (and the report) I can't help thinking if this will finally be the case where the role of 'Accountable Manager' is put under the spotlight.
None of the replies in this post consider management oversight / responsibility or the contribution of a sound and constantly applied Quality Management System may have had in preventing this incident happening in the first place.
The report should help those who ask the question 'what is the cost of quality'......... more importantly the report (and unfortunately the incident) in my view identify the cost of not having quality.
I hope the bean counters and ladder climbers of the world take note and that the court fully understand the deffinition of 'Accountable Manager' and do the right thing.... if it has the teeth that is.
None of the replies in this post consider management oversight / responsibility or the contribution of a sound and constantly applied Quality Management System may have had in preventing this incident happening in the first place.
The report should help those who ask the question 'what is the cost of quality'......... more importantly the report (and unfortunately the incident) in my view identify the cost of not having quality.
I hope the bean counters and ladder climbers of the world take note and that the court fully understand the deffinition of 'Accountable Manager' and do the right thing.... if it has the teeth that is.
Joined: Dec 2007
Posts: 175
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From: Cyprus
5 to be charged with manslaughter for Helios crash including 2 Britons. See
Cyprus Mail Internet Edition 24th Dec.
Cyprus Mail Internet Edition 24th Dec.
Joined: Jul 2006
Posts: 124
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From: Sand Pitt
4 charged with manslaughter over the Helios accident
Cypriot newspaper 'Politis' says today that 4 people have been charged with manslaughter over the Helios accident.
Andreas Drakos, Chief Executice
Demetris Pantazis General Manager
George Kikidis Operations Manager
Ianko Stoimenov, Chief Pilot
Andreas Drakos, Chief Executice
Demetris Pantazis General Manager
George Kikidis Operations Manager
Ianko Stoimenov, Chief Pilot